<u>Answer:</u> The correct answer is Option D.
<u>Explanation:</u>
Reduction reaction is defined as the reaction in which a substance gains electrons. Here, the oxidation state of the substance decreases.
Oxidizing agents are the agents that helps in the oxidation of other substance and itself gets reduced. These agents undergoes reduction reactions.
Oxidation reaction is defined as the reaction in which a substance looses its electrons. Here, oxidation state of the substance increases.
Reducing agents are the agents that helps in the reduction of the other substance and itself gets oxidized. These agents undergoes reduction reactions.
Oxidation state is the number which is given to an atom when it looses or gains electron. It is written as a superscript. In a compound, the total charge is equal to the sum of the charges of all atoms in that compound. <u>For Example:</u> In 
, manganese has +7 oxidation number and oxygen has -2.
So, the charge on the compound = ![[=7+(4\times (-2))]=-1](https://tex.z-dn.net/?f=%5B%3D7%2B%284%5Ctimes%20%28-2%29%29%5D%3D-1)
Hence, the correct answer is Option D.
1 carot = 0.2 grams
1.5 carot = 0.3 grams.
1 mol of Carbon = 12 grams
x mol = 0.3 grams
0.3 * 1 = 12 x
x = 0.3/12
x = 0.025 mol
1 mol of Carbon is 6.02 * 10^23 atoms
0.025 mol of carbon is x
1/0.025 = 6.02*10^23 * /x
x = 0.025 * 6.02 * 10^23
x = 1.5 * 10^22 atoms of carbon.
Answer:
Alchemy is a practice of making gold from other metals.
Explanation:
Alchemy is a method which is practiced by the ancient scientists of Europe, Africa and Asia trying to produced gold from other metals. This method was failed to produced gold from metals and all scientist suggested that metals can not be converted into gold. Greeks were the people who presented the theory of alchemy in the first few centuries of CE.
Answer:
a) a0 was 46.2 grams
b) It will take 259 years
c) The fossil is 1845 years old
Explanation:
<em>An unknown radioactive substance has a half-life of 3.20hours . If 46.2g of the substance is currently present, what mass A0 was present 8.00 hours ago?</em>
A = A0 * (1/2)^(t/h)
⇒ with A = the final amount = 46.2 grams
⇒ A0 = the original amount
⇒ t = time = 8 hours
⇒ h = half-life time = 3.2 hours
46.2 = Ao*(1/2)^(8/3.2)
Ao = 261.35 grams
<em>Americium-241 is used in some smoke detectors. It is an alpha emitter with a half-life of 432 years. How long will it take in years for 34.0% of an Am-241 sample to decay?</em>
t = (ln(0.66))-0.693) * 432 = 259 years
It will take 259 years
<em>A fossil was analyzed and determined to have a carbon-14 level that is 80% that of living organisms. The half-life of C-14 is 5730 years. How old is the fossil?</em>
<em />
t = (ln(0.80))-0.693) * 5730 = 1845
The fossil is 1845 years old
